U.S. military sources serving in North Africa are challenging the latest White House claim that the administration is applying “all the resources” at its disposal to bring the Benghazi attackers to justice, charging instead that the Obama administration knows who is responsible but is not acting.

“They have let it slip by because of politics, and now we’ve taken all the correlation we had and dropped the ball because of risk (aversion) — and now the security in Libya is more fragile than ever,” one U.S. special operator told Fox News. The source, speaking on condition of anonymity, confirms that U.S. forces have tracked the alleged attackers since October but have since lost the trail of some of them, as no one up the chain of command would authorize them to capture or kill the targeted militia members.